From: Matt Carlson <mcarlson@broadcom.com>
Date: Wed, 27 Jul 2011 14:20:50 +0000 (+0000)
Subject: tg3: Add partial fragment unmapping code
X-Git-Tag: v2.6.39-400.9.0~423^2~19^2~11^2~692
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6394130a107d10f31854cf1a604a203022f86df5;p=users%2Fjedix%2Flinux-maple.git

tg3: Add partial fragment unmapping code

The following patches are going to break skb fragments into smaller
sizes.  This patch attempts to make the change easier to digest by only
addressing the skb teardown portion.

The patch modifies the driver to skip over any BDs that have a flag set
that indicates the BD isn't the beginning of an skb fragment.  Such BDs
were a result of segmentation and do not need a pci_unmap_page() call.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e01ee14d499e5d09c0a9db0cac2545a018849e3d)

Signed-off-by: Joe Jin <joe.jin@oracle.com>
---

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 4db20cb0b02f..58e7d59a0b78 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4839,6 +4839,12 @@ static void tg3_tx(struct tg3_napi *tnapi)
 
 		ri->skb = NULL;
 
+		while (ri->fragmented) {
+			ri->fragmented = false;
+			sw_idx = NEXT_TX(sw_idx);
+			ri = &tnapi->tx_buffers[sw_idx];
+		}
+
 		sw_idx = NEXT_TX(sw_idx);
 
 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
@@ -4850,6 +4856,13 @@ static void tg3_tx(struct tg3_napi *tnapi)
 				       dma_unmap_addr(ri, mapping),
 				       skb_shinfo(skb)->frags[i].size,
 				       PCI_DMA_TODEVICE);
+
+			while (ri->fragmented) {
+				ri->fragmented = false;
+				sw_idx = NEXT_TX(sw_idx);
+				ri = &tnapi->tx_buffers[sw_idx];
+			}
+
 			sw_idx = NEXT_TX(sw_idx);
 		}
 
@@ -5932,6 +5945,13 @@ static void tg3_tx_skb_unmap(struct tg3_napi *tnapi, u32 entry, int last)
 			 dma_unmap_addr(txb, mapping),
 			 skb_headlen(skb),
 			 PCI_DMA_TODEVICE);
+
+	while (txb->fragmented) {
+		txb->fragmented = false;
+		entry = NEXT_TX(entry);
+		txb = &tnapi->tx_buffers[entry];
+	}
+
 	for (i = 0; i < last; i++) {
 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
@@ -5941,6 +5961,12 @@ static void tg3_tx_skb_unmap(struct tg3_napi *tnapi, u32 entry, int last)
 		pci_unmap_page(tnapi->tp->pdev,
 			       dma_unmap_addr(txb, mapping),
 			       frag->size, PCI_DMA_TODEVICE);
+
+		while (txb->fragmented) {
+			txb->fragmented = false;
+			entry = NEXT_TX(entry);
+			txb = &tnapi->tx_buffers[entry];
+		}
 	}
 }
 
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 27826a536de8..1cba0905a386 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2655,6 +2655,7 @@ struct ring_info {
 struct tg3_tx_ring_info {
 	struct sk_buff			*skb;
 	DEFINE_DMA_UNMAP_ADDR(mapping);
+	bool				fragmented;
 };
 
 struct tg3_link_config {